Multi-line gluing of superimposed leaves

ABSTRACT

A series of spaced, transverse glue lines and/or one or more longitudinal glue lines, used to join certain of the face-to-face sheets of a continuous web along either or both of its marginal edges, are dried simultaneously, regardless of the width of the web or the spacing between its glue lines, by evaporation of the moisture content of the glue as the web is advanced. Heat energy is applied to the glue lines through use of wave guides that conduct electrical energy in the microwave region, and the amount of heat energy so applied is controlled in accordance with the number of glue lines being dried.

[451 Jan. 2, 1973 [54] MULTI-LINE GLUING OF SUPERIMPOSED LEAVES [75]Inventors: Larry B. Wolfberg; John Harper,

both of Wichita, Kans.

[73] Assignee: Service Business Wichita, Kans.

[22] Filed: Jan. 27, 1971 [21] Appl. No.: 110,186

Related US. Application Data [63] Continuation-impart of Ser. No.882,256, Dec. 4,

1969, Pat. No. 3,584,199.

Forms, Inc.,

[52] US. Cl ..34/1, 219/1055 [51] Int. Cl. ..B0lk 5/00 [58] Field ofSearch ..34/1; 219/1055 [56] References Cited UNITED STATES PATENTS3,197,601 7/1965 Wayne et al ..34/1

3,456,355 7/1969 Cumming et al. ..34/1 3,358,378 12/1967 Downs ..34/13,484,179 12/1969 Adams et al ..34/1 7 3,491,457 l/l970 Schreiber et al...34/1 3,293,765 12/1966 Winkler et al ..34/1

Primary ExaminerCarroll B Dority, Jr. Attorney-Schmidt, Johnson, l-lovey& Williams [5 7 ABSTRACT A series of spaced, transverse glue linesand/or one or more longitudinal glue lines, used to join certain of theface-to-face sheets of a continuous web along either or both of itsmarginal edges, are dried simultaneously, regardless of the width of theweb or the spacing between its glue lines, by evaporation of themoisture content of the glue as the web is advanced. Heat energy isapplied to the glue lines through use of wave guides that conductelectrical energy in the microwave region, and the amount of heat energyso applied is controlled in accordance with the number of glue linesbeing dried.

15 Claims, 16 Drawing Figures Perl? Head MULTI-LINE GLUING OFSUPERIMPOSED LEAVES This is a continuation-in-part of our co-pendingapplication Ser. No. 882,256 filed Dec. 4, 1969 now US. Pat. No.3,584,199 and entitled GLUE FASTENING OF SUPERIMPOSED LEAVES.

In the manufacture of continuous business forms and the like it isextremely important that they be capable of use in automatic,computerized printers and other machines without creating any difficultysuch as jamming, damage to the forms, malfunction of the machines orother problems. This necessitates high perfection in the production ofthe multilayered units whether in the nature of sheets or leaves used asbusiness forms, stationery or otherwise.

By far the most difficult problem is in the line gluing of the sheetstogether. First of all, there must not be any undue bulkiness at thezone of the glue line. Secondly, the increase in thickness necessitatedby the presence of the glue must be uniform and minimal. Thirdly, theglue line may be continuous, if so desired, in absence of spacestherealong where complete interconnection of the sheets cannot beeffected. Fourthly, the interconnection must not give way and permitseparation of the sheets at any point along the glue line either duringproduction, or during storage and shipment, or during use in dataprocessing printing machines or other equipment.

Conventionally, both the so-called hot and cold glues have been used forthis purpose, including both animal and dextrin solutions. And variousheating methods have been tried, including infrared thermal radiation toevaporate the liquid content of the glue and to, therefore, effectdrying. But, except in cases of rather expensive, slow procedures, noprior method has been entirely successful regardless of the type of glueor heating methods employed.

Particularly aggravating has been the problem known as tenting and theproblem of build-up bulk caused by the line of glue. The continuous,multicopy sheets to which the present invention relates are foldedtransversely at equally spaced intervals to present a finished packwhich can not only be conveniently stored and shipped but which willunfold as the same is fed to computerized printers, typewriters andother machines. Defective gluing results in separation of the sheets ateachline of fold, forming a small triangular bulge known as a tent."Such condition cannot be tolerated primarily because of malfunction inthe aforementioned machines with which the forms and the like areultimately used.

Still another problem in the assembly and fastening of a number ofcontinuous leaves of paper for use as above explained relates tomaintaining the sheets in proper alignment. Consequently, each layermust be rather perfectly aligned, edge to edge, with proximal sheetsthereabove. and therebelow so that all material printed or typed on theoriginal will be reproduced on the copies, by the effect of interleavedcarbon, mechanical or chemical self-contained reproducing paper, insubstantially the same location marginally as well as top to bottom.Conventional methods of assembly and interconnection of such continuous,superimposed leaves or sheets of paper through use of glue have notalways solved this problem to the complete satisfaction of all users..

It is an important object of our present invention, therefore, toprovide a drier and methods which will effectively, rapidly and properlyremove the moisture from glue lines whether disposed along either orboth of the marginal edges of the web and regardless of the number ofsuch glue lines being dried simultaneously.

Another important object of the instant invention is the provision of amicrowave drier and methods that utilize wave guides, through which theglue lines pass as the web is advanced continuously, in such manner asto permit control of the application of heat energy in accordance withthe number of glue lines being dried.

Still another important object of the present invention is the provisionof a drier in which the amount of electrical energy conducted by one ofthe wave guides is controlled in accordance with the number of gluelines passing therethrough, and the amount of heat energy applied by asecond wave guide is also controlled according to the number of gluelines passing through the second wave guide.

A further object of our instant invention is to provide a drier inwhichthe control of the heat energy applied by the wave guides iseffected either by variance in the amount of electrical energy whichthey conduct or by varying the dwell time of the glue lines within thefields of the wave guides.

A still further object of the present invention is to provide a drier inwhich the amount of heat energy being applied along one marginal edge ofthe web with respect to the amount of heat energy being applied alongthe other marginal edge of the web may be varied in direct relationshipto the number of glue lines passing through each of the wave guides, allwithout burning of the sheets or failure to remove sufficient moisturefrom any glue line.

Additional aims of our present invention include the provision of adrier wherein the distance between the two primary wave guides may beeasily and quickly changed according to the width of the web beingprocessed; wherein the primary wave guides are connected together by aflexible wave guide, permitting input to but one of the primary waveguides from the magnetron used to produce power at microwavefrequencies; wherein the second primary wave guide may be shifted to aninoperative position when the web is provided with glue lines along butone of its marginal edges; wherein is provided a moisture detector or atemperature sensitive device to insure application of the correct amountof heat energy; and wherein provision is made for effectively removingthe vapors from the wave guides.

FIG. 1 is a schematic, side elevational view of equipment capable of usein carrying out one method of glue fastening of superimposed leaves inaccordance with the concepts of our present invention;

FIG. 2 is a schematic top plan view of the equipment illustrated in-FIG.l; v

FIG. 3 is a perspective view of a pack of continuous business forms orthe like, partially unfolded and with one corner pulled back forillustrating certain details of construction;

FIG. 4 is a fragmentary, top plan view of the forms shown in FIG. 3, theaforementioned corner being broken away for clearness;

FIG. 5 is a transverse cross-sectional view through the formsillustrated in FIG. 3;

FIG. 6 is a fragmentary, longitudinal cross-sectional view through theforms showing one type of cross perforator;

FIG. 7 is a cross-sectional view through one of the nozzles employed inthe equipment shown by FIGS. 1 and 2 for depositing a line of glue ontothe sheets as they are advanced through the collator;

FIG. 8 is a top plan view of a drier adapted for simultaneous drying ofglue lines along either or both marginal edges of the web, parts beingbroken away for clearness;

FIG. 9 is a side elevational view of the drier shown in FlG. 8;

F lG. 10 is a view showing the inlet end thereof;

FIG. 11 is a fragmentary, horizontal cross-sectional view taken belowthe wave guides of the drier shown in FlGS. 8--10.

FlG. 12 is an enlarged, fragmentary, vertical crosssectional viewthrough the two primary wave guides;

FIG. is an enlarged, fragmentary, detailed crosssectional view taken online 1313 of FIG. 11;

FlG. 14 is a schematic view illustrating the step of varying the dwelltime in one of the wave guides;

F IG. 15 is a schematic view showing the structure for detecting thecorrect amount of heat application; and

FIG. 16 is a perspective view of a T form type of coupling for the waveguides to control the application of heat energy in a manner differentfrom the method of FIGS. 1-14.

For convenience, the methods of our present invention will hereinafterbe described in connection with the production of a pack or web 10 ofcontinuous business forms 12 having equally spaced transverse lines ofperforation 14, and especially adapted for use in computerized or dataprocessing printers and other comparable equipment. It is to beunderstood, however, that such terminology does not precludeadvantageous use of our methods in connection with the glue fastening ofsuperimposed leaves or sheets of paper having various other uses,including, therefore, stationery and other products.

The fqgm chosen for illustration of our methods, broadly designated bythe numeral 12 as aforesaid, includes a top sheet or leaf of paper 16, asheet of carbon paper 18 attached to the sheet 16 therebelow, a secondsheet of paper 20 beneath the carbon 18, a second sheet of carbon paper22 beneath the sheet 20 and at tached thereto, and a third or bottomsheet of paper 24 beneath the carbon 22. It is to be understood,however, that in accordance with the methods about to be described, theforms 12 may consist of any number of additional sheets as at 16,20 and24 with a corresponding number of carbons as at 18 and 22. Moreover, itis not necessary, within the principles of our invention, that the pack10 include the carbons 18 and 22, or any carbons, as in the case ofself-contained reproducing paper, nor do we deem ourselves limited tothe lines of perforation 14 because such perforated lines 14 may beeliminated or the continuous sheet 16 and/or sheets 20 and 24 may beentirely severed at the lines indicated by the numeral 14.

Moreover, the product shown in FIGS. 3,4 and 5 may have rows of holes oropenings 26 and 28 adjacent the longitudinal edges of the sheets 16, 20and 24, but since the carbons 18 and 22 do not extend the full width ofthe sheets 16, 20 and 24, the holes 26 and 28 do not pass through thecarbon paper.

Furthermore, the product chosen for illustration is provided with alongitudinal line of perforations 30 which pass through all of thesheets 16, 18, 20, 22 and 24, presenting a marginal stub 32 which may besnapped away after processing through the printer, thereby separatingall of the sheets 16, 18, 20, 22 and 24, and permitting desireddistribution of the individual sheets 16, 20 and 24 when the same aretorn apart along the lines of perforation 14.

To this end, therefore, and in accordance with the method to bedescribed in connection with FlGS. l-7 inclusive, the carbons 18 and 22are attached to their corresponding sheets 16 and 20 respectively bylongitudinal lines of glue 34 within the stub portions 32, i.e.,outwardly of but adjacent the line of perforation 30. On the other hand,the sheet 16 is fastened to the sheet 20, and the sheet 20 is fastenedto the sheet 24 by glue lines 36 extending continuously throughout thelength of the stub 32 adjacent the outermost longitudinal edge thereofwith the holes or openings 28 located between the glue lines 34 and 36.Our present invention relates essentially to the proper formation of theglue lines 36, as will hereinafter appear.

In FIGS. 1 and 2 of the drawing, a collator broadly designated by thenumeral 38 supports the supply drums 40,42,44, 46 and 48 for thecontinuous sheets or leaves 16,18,20,22 and 24 which are advancedhorizontally (from right to left viewing FIGS. 1 and 2), to place suchsheets in superimposed relationship, by rotatable drive rollers 50 whichmay or may not have radial pins at their peripheries for receiving theholes 26 and 28 of the sheets 16, 20 and 24.

Collator 38 is equipped with a number of special nozzles 52 fordepositing a line of glue on the sheets during their advancement. Suchnozzles 52 are especially formed in accordance with the presentinvention, preferably from a non-oxidizing, malleable or nonmalleablematerial of required dimensions, as illustrated in FIG. 7 in thedrawing. It is extremely important that the nozzle direct a very finestream of glue to the sheets, and while we have been successful incarrying out our methods by the selection of an orifice 54 for thenozzles 52 that has a size in the order of from 0.005 to 0.0937 inches,our invention is not necessarily restricted to such dimensions.

Moreover, in order to cause the glue to rise and string out beforereaching the sheets, thus forming narrower glue lines 36 of minimumthickness than is made possible by a standard nozzle, we have cut thehead 56 of the nozzle 52 at an angle of approximately 5, the sheetstraveling with respect to the head 56 in the direction of arrow 58 inFlG. 7.

We have found that the so-called hot glues universally used in manyapplications within this field are not entirely satisfactory for use inconnection with our present method for many reasons including the factthat such glues must be reduced both in temperature and in moisturecontent before they effectively bond the sheets together and there is nosatisfactory drying and cooling means for such glues which will permithigh speed production at relatively low manufacturing costs. Moreover,the hot glues form a jell on reduction of temperature, causing them tograb onto the fibers of the paper too quickly, thereby aggravating theproblem of maintaining the sheets in proper alignment, i.e., with theirholes 26 and 28 in full and direct register.

We have also determined that the conventional animal and dextrin gluesare not entirely satisfactory because of the fact that solids are insuspension within the liquid content thereof such that glues of thattype are too slow to set up and dry and not conducive to obtaining therather large number of desired results made possible through use of ourpresent method.

Therefore, in accordance with our invention, the glue to be dispensedfrom the nozzles 52 is desirably a cold glue that is easy to handle,requiring no heat to maintain it in a fluid condition and requiring noequipment for reduction of the temperature thereof, it beingcontemplated that the glue emanating from the nozzles 52 be at roomtemperature. In this connection we prefer to use an emulsion having apolyvinyl base with a water content of approximately 40 percent,including the usual plastercizers, and having the polyvinyl acetatesolids emulsified therein, as distinguished from dextrin and animalsolutions, wherein the solid particles are in ordinary suspension.

Depending upon the base resin, such glues tend to set rather quickly,particularly upon application of pressure, and thereupon are capable ofrapid evaporation of their moisture content. Therefore, as soon as thesheets 20 and 24 come into engagement with the glue lines 36 thereabove,such glue tends to immediately grab onto the fibers of the papers andhold them against slippage relatively, but, by the same token, theselected glue is characterized by the fact that sufficient relativeslippage between the sheets 16, 20 and 24 is permitted to maintain theholes 26 and 28 aligned and in register while the remaining steps of theprocess are carried out. i

In accordance with our method also, we prefer to use pulsed microwaveenergy to generate internal heating of the glue in a concentrated areawhich may be confined to approximately inch wide or less, therebycausing rapid drying and bonding in the stub construction 32 ofcontinuous as well as snap-apart business forms and stationary. Suchmicrowave internal heating in a concentrated area, as distinguished frominduced heating over the entire form area, can be produced through useof a magnetron 60 in which the flow of electrons is controlled by anexternally applied magnetic field to generate power at microwavefrequencies, such very short electromegnetic waves normally beingbetween approximately 100 centimeters and one centimeter in wave length.Such microwaves, in the vicinity of about 2,400 megacycles, are capableof developing tremendous heat and energy, combined in a relatively smallspaceconducted to the exact zone where heat is needed withoutintroduction of undesired heat into those areas of the sheets where thepaper and the carbon might be adversely affected, which has been adetriment to optimum results in all previous systems and methods.Accordingly, the wave guide section 62 of the magnetron generator 60need not exceed more than approximately four feet in length therebyreducing the drying time to a minimum and permitting high speedproduction. Such internal heating of the glue to evaporate its moisturecontent prevents damage to the carbon papers 18 and 22 because their oilbased carrying agent will not dry out, not will there be any spoilage ofthe paper sheets 16, 20 or 24 by burning or scorching.

It has been found advisable also to use pinned drums, rollers or thelike 64 at the drying section to move the superimposed sheetssimultaneously along the section 62 and maintain them in properalignment until such time as the glue is completely dry and full andeffective bonding of the sheets together has been effected. As abovementioned, the glue which we have selected permits sufficient slippageof the sheets relatively to cause such proper alignment during firstcontact of the paper parts. Yet, because of the fastsetting'characteristics-of the glue after water has been removed bymicrowave created heat, the complete, firm and final fastening of thesheets one to another is made possible during the very short periodduring which the glue lines 36 are subjected to the generator 60.

From the dryer 60 the sheets are advanced through a perforating head 64to produce the transverse lines of perforation 14. It is of coursepossible to interpose the head 64 ahead of the dryer 60, but the step ofperforating tends to shift the sheets out of alignment and we have,therefore, found it to be preferable to have complete and firm bondingof the sheets prior to subjecting them to the perforator 64.

In FIG. 6 of the drawing there is illustrated upper and lowerperforating drums 66 and 68 provided with diametrically opposedperforating blades 70 and 72 respectively and timed in their rotationsuch as to alternately perforate the sheets along the lines 14 from thetop and from thebottom. Such alternating function of the drums 66 and 68of the head 64 is advantageous from the standpoint of proper folding infolder section 74 along the lines 12 to produce the pack 10 as shown inFIG. 3. Alternately, the drum 68 could be in the form of an anvil withall of the blades on the drum 66 such that formation of the lines 14would be from the top only, but such arrangement causes a back-fold onevery other cross perforation which limits the number of superimposedsheets to no more than eight and in turn is less desirable than drums ofthe kind illustrated at 66 and 68 in FIG. 6 of the drawing.

lt is now apparent that with the sheets 16, 20 and 24 fully and properlybonded together along the glue lines 36, there will be no separation ortenting at the lines of fold along the perforation lines 14,eliminating, therefore, the problems of jamming and other malfunctionswhich are quite common in the use of a product of this nature inprinting machines and other equipment.

In order to accomplish the desired results as hereinabove initiallyoutlined, it is also extremely important that the glue lines 36 be verynarrow and of minimal thickness for many reasons. By providing for onlysufficient surface impregnation of the paper fibers such as to effectgood bonding, the stub area 32 will not become unduly rigid andinflexible along the glue lines 36, not only making it possible to formthe sheets into a compact stack 10, but reducing problems incident tothe feeding of the forms through computerized printers and the like.Such minimum bulkiness at the glue lines 36 is made possible by applyingthe glue continuously and uniformly and by selection of a glue nozzle,as well as a drying process, which will eliminate zones of separationalong the glue lines 36 and eliminate formation of dried glue crystals,lumps and the like which are incapable of holding the sheets properlybonded together.

It is to be understood also that our method is not limited to the use ofthe glue line 36 only along one longitudinal edge of the forms 12; incertain instances it is desirable or necessary to duplicate the glueapplying and drying steps along that edge of the forms 12 having theopenings or holes 26 therein. Our invention is also fully adaptable foruse in making various types of snapout forms, as above indicated.Moreover, it is not necessary to utilize the stub feature 32 with theline of performations 30 in the manner and for the purpose abovedescribed.

Concentrated heating along the glue lines 36 is important because itavoids damage to the carbons 18 and 22. In some instances, processedcarbons are used having the same width as the sheets 16, 20 and 25 withthe holes 26 and 28 also passing through the carbon sheets. However, themarginal edges are kraft paper, not carbonized; hence, even in suchinstances our method will not damage the adjacent carbon areas.

Our invention also contemplates a complete and proper method offastening the entire set of forms together by the application of theglue lines to the face and back of paper sheet 20, whereby the gluelines'are applied so as to fasten the paper to the carbon below, andthis carbon in turn is fastened to the sheet below it, thusaccomplishing the manufacture of extremely flexible forms which willallow the complete set to pass easily around the platen of a typewriteror a computer printer which utilizes a small, round platen and,therefore, is more prone to jam when a bulky form is passed over andaround the small platen. This is to be done by the use of processedcarbon paper with the holes 26 and 28 also passing through the carbonsheets, thus allowing the pins on the drums to function in theircapacity of moving the sheets forward while the gluing and dryingfunctions are being performed. Under special conditions where a widerstub is permissible, this form of construction can be effected withoutthe use of the holes 26 and 28 in the carbon, by moving the carbon awayfrom the edge and applying the glue and microwave heat to the form onthe inside areas of the pin feed device.

Important also is the fact that our method may be accomplished withoutthe necessity of using slow speed zigzag type folders with tuckerblades, thereby enabling the use of high speed folding equipment suchas, but not limited to, spiral and/or air jet or vacuum type foldersoperating at their fullest rated speed and capacity.

While application of the adhesive is in the form of a continuous,elongated, narrow, thin line, which is preferred, our invention is alsoadaptable to spot gluing or to interrupted lines. In certain instancesit may be desirable, for example, to omit the glue at the lines of fold.

Web 12 may also be used in connection with a drier 100 shown in FIGS.8-13, with two or more sheets 16, 20, 24, etc., having one or morelongitudinal glue lines 36 (or rows of glue spots) along each or both ofthe marginal edges of the web 12. That is to say, all of two or moresheets may be joined by glue lines 36 along either or along bothmarginal edges of the web 12, or there may be one or more glue lines 36along one edge of web 12 and a greater or lesser number of glue lines 36along the other edge of web 12, with or without carbons 18, 22, etc.,and with or without stubs 32.

To this end then, there is provided a magnetron 102 for producing powerat microwave frequencies and directing the electromagnetic waves soproduced along a first primary, elongated tubular wave guide 104 that itparallel with the path of travel of the web 12. The electrical energy,received at one end of the main wave guide transmission line 104 is thendirected from the opposite end of the latter to an elbow joint 106coupling the wave guide 104 with a flexible, diagonally disposed waveguide 108. Another elbow joint or wave guide U l 10 directs the energyinto a second primary wave guide 112 that is shiftable into and out ofparallelism with the wave guide 104, as well as into and out of the samehorizontal plane as the wave guide 104. Manifestly, each of thejunctures 106 and 110 has a curvature for preventing power loss throughreflection and is otherwise properly designed in accordance withspecifications well-known and understood by those skilled in the art oftransmission of microwave energy to branch stubs.

While rectangular wave guides 104, 108 and 122 have been chosen forillustration, they may be circular in cross section if desired, e.g.,coaxial cables, and the wave guides 104 and 112 are each provided with alongitudinal slot 114 (FIG. 12) along its inner face for clearing themarginal edges of the web 12 as it is advanced from right to left,viewing FIGS. 8, 9, 1 1, 14 and 15. Longitudinally extending reflectors116 rigidly mounted within the wave guides 104, and 112, havelongitudinal grooves 118 aligned with the slots 114 for receiving thecorresponding marginal edges of web 12 to closely concentrate theelectrical energy within the zones of the glue lines 36.

The web 12 is supported during its advancement through the drier 100 bya panel 120 between the wave guides 104 and 112 and above the wave guide108. Oppositely facing channel brackets 122 and 124, the latter of whichis carried by a wave guide 104, removably support any one of a number ofpanels 120 of differing widths, depending on the widths of the webs 12being processed.

While wave guide 104 is rigidly supported by the magnetron 102, the waveguide 112 is carried by a polygonal frame 126 disposed beneath the waveguide 108 and swingable about horizontal pintles 128 carried by spacedupstanding standards 130 of a main frame 132 (FIGS. 10 and 11). Frame132 also carries a U- shaped bracket 134 having upstanding legs 136which have openings 138 (FIG. 9) for receiving spring loaded pins 140 onframe 126 that releasably hold the latter in its normal, horizontal,operating position. Raising and lowering of the frame 126 about pintles128 is effected by turning a crank 142 of a screw 144 rotatablysupported by frame 132 and depending from the frame 126. The upper endof screw 144 is rotatably attached to frame 126 within a slot 146 (FIG.1 l

Frame 126 supports a plate 148 for swinging movement about a normallyvertical pin 150 there being a number of bolt-slot guides 152 for plate148 (FIG. 11 and 13), one of which (designated 152a) may be used toreleasably clamp the plate 148 to the frame 126. On release of suchclamp 152a, an eccentrically mounted cam 154, carried by frame 126within an oval slot 156 formed in plate 148, is used to swing the latterabout pin 150 by oscillation of a handle 158 rigid to cam 154.

Plate 148 has four upstanding corner posts 160 which rotatably support apair of screws 162 and 164 joined by a chain and sprocket wheel assembly166, screw 164 being provided with a handle 168. The wave guide 112 isrigidly secured to follower blocks 170 threaded on the screws 162 and164.

Wave guides 104 and 112 are each provided with a row of escape holes 172for steam vapor but such vapors may also be withdrawn from the waveguide 112 by a suction blower 174 on a chamber 176 that is in turnsupported by follower blocks 170. Chamber 176 communicates with vaporports 176 in wave guide 112, and blower 174 is provided with a vaporoutlet 180. A similar suction blower arrangement may be provided for thewave guide 104 if desired or needed.

In operation, as the web 12 is directed along the panel 120 in thedirection of the arrow in FIG. 14, its marginal edges pass along theslots 114 of the wave guides 104 and 112 and the glue lines 36 passalong the grooves 118 of the reflectors 116, subjecting the glue linesto the action of the electrical energy concentrated in the grooves 1 18.The glue lines 36 absorb such electrical energy to thereby apply heatenergy and thus raise the temperature of the glue lines 36, causingevaporation of the moisture thereof. In the event that an equal numberof glue lines 36 is placed along each of the marginal edges of web 12,the amount of electrical energy input to the wave guides 104 and 112,and therefore the amount of heat energy applied to all of the glue lines36 will normally be the same. A control panel 182 on the casing of themagnetron generator 102 is illustrated in FIG. 8-10, the controlsincluding an automatic tuning assembly and a control knob 184 foradjusting the energy input to that end of wave guide 104 opposite to thejuncture 106.

Manifestly, too much heat will tend to burn or scorch the web 12 or, ifthe remaining moisture content of the glue lines 36, after the web 12leaves the drier 100 is too high, the glue lines 36 have not beensufficiently dried. Therefore, as an indication to the operator thatadjustment of the input energy should be made, there are provided asshown in FIG. 15, moisture detecting devices or temperature sensitivedevices 186 to read out the conditions existing at the trailing ends ofthe wave guides 104 and 112. Devices 186 are aligned with thecorresponding energy fields and may be operably coupled with an alarm188, such as a bell or buzzer, through a read-out relay 190.

The load to which the energy fields are subjected depends upon thenumber of sheets 20 passing therethrough, the nature of the paper orother materials from which the sheets 20 are made, the number of gluelines 36 and the temperature and humidity conditions, the speed ofadvancement of the web 12, and many other factors. Thus, by observingthe web 12 as it passes beyond the devices 186 to detect any excessheating, and by listening for the alarm 188, the operator may quicklyand easily make the proper adjustment by manipulation of the knob 184 orby adjusting the position of the glue line in relation to the energyfield.

Drier 100 is also capable of handling webs" 12 of various widths. It isbut necessary to manipulate the handle 168 in order to shift the waveguide 112 toward and away from the wave guide 104. Rotation of screw164.

also rotates the screw 162 through assembly 166, causing the followers170 to travel along the screws 162 and 164. The flexibility of waveguide 108 permits such adjustment, and panels of suitable widths may bethen interchanged in the brackets 122 and 124.

In the event that the load on the electrical energy passing along thewave guide 112 is less than the load on the electrical energy passingalong the wave guide 104, as for example, a fewer number of glue lines36 being dried by the wave guide 112, the application of heat energywithin the wave guide 112 may be controlled separately from the waveguide 104. This is accompllshed by varying the amount of electricalenergy to which the glue lines 36 in wave guide 112 are subjected. It isbut necessary to release the clamp 152a and turn the handle 158 in orderto swing the plate 148 about the pivot pin 150, causing the wave guide112 to swing out of parallelism with the wave guide 104 as illustratedin FIG. 14.

Thus, the glue. lines 36 subjected to the energy field of wave guide 112dwell therein for a lesser period of time than the glue lines 36subjected to the energy field of wave guide 104. FIG. 14 illustrates theway in which the marginal edge of web 12 proximal to wave guide 112emerges from within the latter before the opposite marginal edge of web12 emerges from wave guide 104, thereby providing for the dwell timedifferential. After handle 158 has been rotated to the properadjustment, clamp 152a is then again manipulated to hold the plate 148rigidly attached to the frame 126. It is to be noted that the amount ofmovement of plate 148 is rather slight, permitting the bracket 122 toshift relative to panel 120 without releasing the latter.

In connection with the above, either or both of the wave guides 104 and112 may be so adjusted for dwell time variance by merely providing thewave guide 104 with a swingable supporting plate 148 of the kind abovedescribed. Moreover, either or both of the wave guides 104 or 112 may beshifted through a manipulation of handle 168 by alteration of thestructure specifically shown and described above.

Oftentimes, large runs over a considerable period of time are made withwebs 12 having one or more glue lines along but one of its marginaledges, in which event it is desirable to move the wave guide 112entirely out of the way. Retraction of wave guide 112 through use of thehandle 168 and removal of panel 120, followed by a release of the pinfrom within the openings 138 and manipulation of the crank 142 willcause screw 144 to swing the frame 126 downwardly about the pintles 128(FIG. 10). This places the wave guide 112 essentially below the level ofthe advancing web 12. A releasable connection 191 is provided betweenthe wave guides 104 and 108, permitting the latter to be swung out ofthe way into underlying relationship to wave guide 112, whereupon theend of wave guide 104 proximal to connection 191 is suitably capped.

Still another method of controlling application of heat energy inaccordance with the number of glue lines being dried, by varying theamount of electrical energy to which the web 12 is subjected, may beprovided by the use of a T form 192 of the kind shown in FIG. 16. Form192 is commonly referred to as the magic" or hybrid T and is providedwith four arms 194, 196, 198 and 200 and with two matching devices 202and 204. Form 192 may be used either as a substitute for the juncture106 or the juncture 110, or may be installed between the magnetron 102and the wave guide 104.

If the electrical energy is directed into arm 194 and the outer ends ofarms 196 and 200 are effectively closed so as to eliminate reflectiontherein, no power will be carried by arm 198; all of the energy willpass into arms 196 and 200. On the other hand, if the wave is directedinto arm 198 and the remaining arms are closed to absorb withoutreflection, no power will pass into arms 196 and 200.

But, if arms 194 and 198 are matched at their terminations so as toeliminate reflections, arm 196 is unmatched, and the energy is fed toarm 198, a reflection will be effected in arm 196. The reflected wavewill return to the common juncture of the arms, producing power flow inarms 194, 198 and 200. If arms 196 and 200 are not matched at theirclosed ends, the energy directed to arm 198 will flow along arm 194.

Accordingly, if form 192 is used in lieu of juncture 106, the amount ofenergy from wave guide 104 to wave guide 108, and therefore, wave guide112, maybe adjusted in accordance with the heat energy requirements ofthe wave guide 112. The same results can be accomplished by using form192 in lieu of the juncture 110. When used between the magnetron 100 andthe wave guide 104, the form 192 may be employed be as a heat sink orfor the purpose of directing the energy from a single power supply 100into two separate driers.

It can now be seen that components have been provided to enable eithersimultaneous gluing along both edges of web 12 in varying distances fromthe normal right hand lines 36 of glue, or, optionally, on either theoutboard" or inboard side or edge of the web 12. Because of the varyingdistances that the outboard glue lines 36 may be required from theregular inboard" lines 36 of glue, there are provided practical methodsof moving or otherwise controlling the confined narrow band of microwaveenergy conducted by wave guide 112. Inasmuch as the balance of themicrowave energy on either or both inboard and outboard" sides isimportant, as is the design and tolerance required within the waveguides themselves for conveying microwave energy throughout the waveguides, there is presented a drier 100 which may be successfully usedwith varying distances between the glue lines 36 and which also has asimple method of balancing the energy on either the inboard or outboardwave guide. Drier 100 permits adjustment wherein the outboard microwaveenergy may be applied 100 percent or varied below I percent ofeltectiveness as conditions require.

We have also found that it is desirable to provide for theaforementioned automatic tuning which tunes the microwave chambers tothe most optimum resonance for drying the glue at any power setting.This is important for efficient operation of our novel methods, and whenused in conjunction with the variable angle of the outboard" wave guide112 in relationship to correspond to the lines of glue 36, there arepresented two novel features that are microwave drying of the lines ofglue on computer forms.

important to successful The arrangement is such that the changeover fromsingle to double glue lines 36 will not require more down time than isneeded to bring the second stub drier 112 into position without thenecessity of removing or adding any loose sections to the assembly. Thewave guide 108 connecting the two assemblies 104 and 112 may be releasedwithout the use of bolts, screws or other inconvenient devices. This isaccomplished by the use of the quick release clamp mechanism 191 whichinterconnects the wave guides 104 and 1 12 when needed, or properlyterminates the wave guide 112 when using drier for single stub modeonly.

The generator 102 must be capable of maintaining stability over alloperating conditions, and the regulating of power to the outboard sidemay be effected by the variation of angle of the stub 112 in relation tothe inboard chamber 104 by the use of the plate 148 mounting of the waveguide 112, which is pivoted at to allow the necessary variation of angleof approach, thus regulating the amount of heat without the necessity ofrequiring a double tuning system. In order to simplify' the operatorsrequirements, the automatic tuning will compensate for varying loadspassing through the machine 100 without the necessity of the operatorhaving to retune to resonance as the conditions change. This will allowthe operator to apply the required amount of heat to any given form 12merely by setting the energy control 184, eliminating the necessity oftuning. This feature in conjunction with the variable angle or thevariable energy flow of the wave guide 112 produces a commerciallyusable drier 100 with minimum amount of adjustment and changeoverrequirements. Also, in order to effect a clean configuration of thecomplete apparatus 100, the wave guide 112 is hinged at 128 in suchmanner as to descent into the area below the level of web 12 when waveguide 112 is not in use.

While the above description has been directed solely to longitudinalglue lines, and to the manufacture of more or less regular type businessforms, our invention is also applicable to the drying of transverse gluelines as well as to the manufacture of specialty type business forms.For example, continuous webs of envelopes requiring remoist type gluesmay also be advanced through a microwave energy field in accordance withthe concepts above set forth by use of a wave guide in the nature of apair of spaced apart plates between which the web is advanced. In thismanner, a series of longitudinally spaced glue lines disposedtransversely of the web may be rapidly and effectively dried, keeping inmind proper dwell time and/or required energy control. Wave guides ofsuch nature may be used also to dry one or more longitudinal glue linessimultaneously with or separately from the drying of a series oftransverse glue lines.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:

1. A drier for removing moisture from one or more glue lines extendinglongitudinally along each or both marginal edges of a web of continuoussheets, arranged in face-to-face relationship, as the web is advancedalong a predetermined path of travel, said drier includmg:

an elongated wave guide adapted for conduction of electrical energy inthe microwave region and disposed along each of said edges respectively,

said wave guides having longitudinal clearance slots for passage of saidedges therealong and through the wave guides as the web is advanced,whereby the glue lines absorb said electrical energy to thereby applyheat energy and raise the temperature of the glue lines, causingevaporation of said moisture thereof; and

structure for controlling said application of the heat energy inaccordance with the number of glue lines being dried, said structureincluding means for shifting at least one of said wave guides to any oneof a number of positions where the proximal edge of the web passesthrough only a portion of said one wave guide. 2. A drier as claimed inclaim 1 wherein said one wave guide is normally parallel with saidproximal edge and wherein said shifting means positions the one waveguide into angular relationship to said proximal edge.

3. A drier for removing moisture from one or more glue lines extendinglongitudinally along each or both marginal edges of a web of continuoussheets, arranged in face-to-face relationship, as the web is advancedalong a predetermined path of travel, said drier including:

an elongated wave guide adapted for conduction of electrical energy inthe microwave region and disposed along each of said edges respectively,

said wave guides having longitudinal clearance slots for passage of saidedges therealong and through the wave guides as the web is advanced,whereby the glue lines absorb said electrical energy to thereby applyheat energy and raise the temperature of the glue lines, causingevaporation of said moisture thereof,

there being a source of said electrical energy coupled with one of saidwave guides,

the other of said wave guides receiving its electrical energy from saidone wave guide through a third wave guide coupling the one wave guidewith said other wave guide; and

structure for controlling said application of the heat energy inaccordance with the number of glue lines being dried,

said structure including means for varying the amount of the electricalenergy input to said other wave guide,

said means including a detachable coupling for said third wave guide.

4. A drier as claimed in claim 2 wherein is provided a support, saidshifting means including a member swingable on the support and havingmeans mounting said one wave guide thereon.

5. A drier as claimed in claim 4 wherein said mounting means is movableon the member for varying the distance between the wave guides.

6. A drier as claimed in claim 2 wherein 'a source of said electricalenergy is coupled with one of said wave guides, and the other of saidwave guides receives its electrical energy from said one wave guidethrough a third wave guide coupling the one wave guide with said otherwave guide, wherein said wave guides are provided with a detachableconnection for conduction of said electrical energy therebetween, andwherein said third wave guide is swingable to an inoperative positionwhen said connection is detached.

7. A drier for removing moisture from one or more glue lines extendinglongitudinally along each or both marginal edges of a web of continuoussheets, arranged in face-to-face relationship, as the web is advancedalong a predetermined path of travel, said drier including:

an elongated wave guide adapted for conduction of electrical energy inthe microwave region and disposed along each of said edges respectively,

said wave guides having longitudinal clearance slots for passage of saidedges therealong and through the wave guides as the web is advanced,whereby the glue lines absorb I said electrical energy to thereby applyheat energy and raise the temperature of the glue lines, causingevaporation of said moisture thereof;

a source of said electrical energy being coupled with one of said waveguides,

the other of said wave guides receiving its electrical energy from saidone wave guide through a third wave guide coupling the one wave guidewith said other wave guide; and means for varying the distance betweensaid one wave guide and said other wave guide in accordance with thedistance between the glue lines along one of said edges and the gluelines along the other of said edges, said third wave guide beingflexible. 8. A drier as claimed in claim 6 wherein said structureincludes means for varying the amount of electrical energy input to saidother wave guide.

9. A drier for removing moisture from one or more glue lines extendinglongitudinally along each or both marginal edges of a web of continuoussheets, arranged in face-to-face relationship, as the web is advancedalong a predetermined path of travel, said drier including:

an elongated wave guide adapted for conduction of electrical energy inthe microwave region and disposed along each of said edges respectively,

said wave guides having longitudinal clearance slots for passage of saidedges therealong and through the wave guides as the web is advanced,whereby the glue lines absorb said electrical energy to thereby applyheat energy and raise the temperature of the glue lines, causingevaporation of said moisture thereof,

there being a source of said electrical energy coupled with one of saidwave guides,

the other of said wave guides receiving its electrical energy from saidone wave guide through a third wave guide coupling the one wave guidewith said other wave guide; and

structure for controlling said application of the heat energy inaccordance with the number of glue lines being dried,

said structure including a first means for varying the amount "ofelectrical energy input to said one wave guide, and a second means forvarying the amount of electrical energy input to said other wave guide.

10. A drier for removing moisture from one or more glue lines extendinglongitudinally along each or both marginal edges of a web of continuoussheets, arranged in face-to-face relationship, as the web is advancedalong a predetermined path of travel, said drier including:

an elongated wave guide adapted for conduction of electrical energy inthe microwave region and disposed along each of said edges respectively,

said wave guides having longitudinal clearance slots for passage of saidedges therealong and through the wave guides as the web is advanced,whereby the glue lines absorb said electrical energy to thereby applyheat energy and raise the temperature of the glue lines, causingevaporation of said moisture thereof,

there being a source of said electrical energy coupled with one of saidwave guides,

the other of said wave guides receiving its electrical energy from saidone wave guide through a third wave guide coupling the one wave guidewith said other wave guide; and

structure for controlling said application of the heat energy inaccordance with the number of glue lines being dried,

said structure including means for varying the amount of electricalenergy input to said other wave guide,

said structure including means for varying the amount of electricalenergy from said one wave guide to said third wave guide. 11. A drierfor removing moisture from one or more glue lines extendinglongitudinally along each or both marginal edges of a web of continuoussheets, arranged in face-to face relationship as the web is advancedalong a predetermined path of travel, said drier includan elongated waveguide adapted for conduction of electrical energy in the microwaveregion and disposed along each of said edges respectively,

said wave guides having longitudinal clearance slots for passage of saidedges therealong and through the wave guides as the web is advanced,whereby the glue lines absorb said electrical energy to thereby applyheat energy and raise the temperature of the glue lines, causingevaporation of said moisture thereof,

there being a source of said electrical energy coupled with one of saidwave guides,

the other of said wave guides receiving its electrical energy from saidone wave guide through a third wave guide coupling the one wave guidewith said other wave guide; and

structure for controlling said application of the heat energy inaccordance with the number of glue lines being dried,

said structure including means for varying the amount of electricalenergy input to said other wave guide,

said structure including means for varying the amount of electricalenergy from said third wave guide to said other wave guide.

12. A method of removing moisture from one or more glue lines extendinglongitudinally along each or both marginal edges of a web of continuoussheets, arranged in face-to-face relationship, said method including thesteps of:

advancing the web along a path of travel parallel with said edges;

subjecting said edges to a field of electrical energy in the microwaveregion flowing along each of said edges respectively as the web isadvanced,

whereby the glue lines absorb said electrical energy to thereby applyheat energy and raise the temperature of the glue lines, causingevaporation of said moisture thereof; and

varying the dwell time of one of said edges in one of said fields withrespect to the dwell time of the other of said edges in the other ofsaid fields whereby to control said application of the heat energy alongsaid one edge in accordance with the number of glue lines being driedalong said one edge.

13. A method as claimed in claim 12, and varying the amount ofelectrical energy input to said other field in accordance with thenumber of glue lines being dried by said other field.

14. A drier for removing moisture from one or more glue lines extendinglongitudinally along each or both marginal edges of a web of continuoussheets, arranged in face-to-face relationship, as the web is advancedalong a predetermined path of travel, said drier includmg:

an elongated wave guide adapted for conduction of electrical energy inthe microwave region and disposed along each of said edges respectively,said wave guides having longitudinal clearance slots for passage of saidedges therealong and through the wave guides as the web is advanced,whereby W the glue lines absorb said electrical energy to thereby applyheat energy and raise the temperature of the glue lines, causingevaporation of said moisture thereof,

there being a source of said electrical energy coupled with one of saidwave guides, the other of said wave guides receiving its electricalenergy from said one wave guide through a third wave guide coupling theone wave guide with said other wave guide; and

structure for controlling said application of the heat energy by eachwave guide respectively in accordance with the relationship of thenumber of glue lines along one of said edges to the number of glue linesalong the other of said edges. 15. A drier for removing moisture fromone or more glue lines extending longitudinally along each or bothmarginal edges of a web of continuous sheets, arranged in face-to-facerelationship, as the web is advanced along a predetermined path oftravel, said drier includmg:

an elongated wave guide adapted for conduction of electrical energy inthe microwave region and disposed along each of said edges respectively,

said wave guides having longitudinal clearance slots for passage of saidedges therealong and through the wave guides as the web is advanced,whereby the glue lines absorb said electrical energy to thereby applyheat energy and raise the temperature of the glue lines, causingevaporation of said moisture thereof; and

structure for controlling said application of the heat energy inaccordance with the number of glue lines being dried,

said structure including means for varying the dwell time of one of saidedges within one of said wave guides independently of the dwell time ofthe other of said edges within the other of said wave guides.

1. A drier for removing moisture from one or more glue lines extendinglongitudinally along each or both marginal edges of a web of continuoussheets, arranged in face-to-face relationship, as the web is advancedalong a predetermined path of travel, said drier including: an elongatedwave guide adapted for conduction of electrical energy in the microwaveregion and disposed along each of said edges respectively, said waveguides having longitudinal clearance slots for passage of said edgestherealong and through the wave guides as the web is advanced, wherebythe glue lines absorb said electrical energy to thereby apply heatenergy and raise the temperature of the glue lines, causing evaporationof said moisture thereof; and structure for controlling said applicationof the heat energy in accordance with the number of glue lines beingdried, said structure including means for shifting at least one of saidwave guides to any one of a number of positions where the proximal edgeof the web passes through only a portion of said one wave guide.
 2. Adrier as claimed in claim 1 wherein said one wave guide is normallyparallel with said proximal edge and wherein said shifting meanspositions the one wave guide into angular relationship to said proximaledge.
 3. A drier for removing moisture from one or more glue linesextending longitudinally along each or both marginal edges of a web ofcontinuous sheets, arranged in face-to-face relationship, as the web isadvanced along a predetermined path of travel, said drier including: anelongated wave guide adapted for conduction of electrical energy in themicrowave region and disposed along each of said edges respectively,said wave guides having longitudinal clearance slots for passage of saidedges therealong and through the wave guides as the web is advanced,whereby the glue lines absorb said electrical energy to thereby applyheat energy and raise the temperature of the glue lines, causingevaporation of said moisture thereof, there being a source of saidelectrical energy coupled with one of said wave guides, the other ofsaid wave guides receiving its electrical energy from said one waveguide through a third wave guide coupling the one wave guide with saidother wave guide; and structure for controlling said application of theheat energy in accordance with the number of glue lines being dried,said structure including means for varying the amount of the electricalenergy input to said other wave guide, said means including a detachablecoupling for said third wave guide.
 4. A drier as claimeD in claim 2wherein is provided a support, said shifting means including a memberswingable on the support and having means mounting said one wave guidethereon.
 5. A drier as claimed in claim 4 wherein said mounting means ismovable on the member for varying the distance between the wave guides.6. A drier as claimed in claim 2 wherein a source of said electricalenergy is coupled with one of said wave guides, and the other of saidwave guides receives its electrical energy from said one wave guidethrough a third wave guide coupling the one wave guide with said otherwave guide, wherein said wave guides are provided with a detachableconnection for conduction of said electrical energy therebetween, andwherein said third wave guide is swingable to an inoperative positionwhen said connection is detached.
 7. A drier for removing moisture fromone or more glue lines extending longitudinally along each or bothmarginal edges of a web of continuous sheets, arranged in face-to-facerelationship, as the web is advanced along a predetermined path oftravel, said drier including: an elongated wave guide adapted forconduction of electrical energy in the microwave region and disposedalong each of said edges respectively, said wave guides havinglongitudinal clearance slots for passage of said edges therealong andthrough the wave guides as the web is advanced, whereby the glue linesabsorb said electrical energy to thereby apply heat energy and raise thetemperature of the glue lines, causing evaporation of said moisturethereof; a source of said electrical energy being coupled with one ofsaid wave guides, the other of said wave guides receiving its electricalenergy from said one wave guide through a third wave guide coupling theone wave guide with said other wave guide; and means for varying thedistance between said one wave guide and said other wave guide inaccordance with the distance between the glue lines along one of saidedges and the glue lines along the other of said edges, said third waveguide being flexible.
 8. A drier as claimed in claim 6 wherein saidstructure includes means for varying the amount of electrical energyinput to said other wave guide.
 9. A drier for removing moisture fromone or more glue lines extending longitudinally along each or bothmarginal edges of a web of continuous sheets, arranged in face-to-facerelationship, as the web is advanced along a predetermined path oftravel, said drier including: an elongated wave guide adapted forconduction of electrical energy in the microwave region and disposedalong each of said edges respectively, said wave guides havinglongitudinal clearance slots for passage of said edges therealong andthrough the wave guides as the web is advanced, whereby the glue linesabsorb said electrical energy to thereby apply heat energy and raise thetemperature of the glue lines, causing evaporation of said moisturethereof, there being a source of said electrical energy coupled with oneof said wave guides, the other of said wave guides receiving itselectrical energy from said one wave guide through a third wave guidecoupling the one wave guide with said other wave guide; and structurefor controlling said application of the heat energy in accordance withthe number of glue lines being dried, said structure including a firstmeans for varying the amount of electrical energy input to said one waveguide, and a second means for varying the amount of electrical energyinput to said other wave guide.
 10. A drier for removing moisture fromone or more glue lines extending longitudinally along each or bothmarginal edges of a web of continuous sheets, arranged in face-to-facerelationship, as the web is advanced along a predetermined path oftravel, said drier including: an elongated wave guide adapted forconduction of electrical energy in the microwave region and disposedalong each of said edges respectively, said wave guidEs havinglongitudinal clearance slots for passage of said edges therealong andthrough the wave guides as the web is advanced, whereby the glue linesabsorb said electrical energy to thereby apply heat energy and raise thetemperature of the glue lines, causing evaporation of said moisturethereof, there being a source of said electrical energy coupled with oneof said wave guides, the other of said wave guides receiving itselectrical energy from said one wave guide through a third wave guidecoupling the one wave guide with said other wave guide; and structurefor controlling said application of the heat energy in accordance withthe number of glue lines being dried, said structure including means forvarying the amount of electrical energy input to said other wave guide,said structure including means for varying the amount of electricalenergy from said one wave guide to said third wave guide.
 11. A drierfor removing moisture from one or more glue lines extendinglongitudinally along each or both marginal edges of a web of continuoussheets, arranged in face-to-face relationship as the web is advancedalong a predetermined path of travel, said drier including: an elongatedwave guide adapted for conduction of electrical energy in the microwaveregion and disposed along each of said edges respectively, said waveguides having longitudinal clearance slots for passage of said edgestherealong and through the wave guides as the web is advanced, wherebythe glue lines absorb said electrical energy to thereby apply heatenergy and raise the temperature of the glue lines, causing evaporationof said moisture thereof, there being a source of said electrical energycoupled with one of said wave guides, the other of said wave guidesreceiving its electrical energy from said one wave guide through a thirdwave guide coupling the one wave guide with said other wave guide; andstructure for controlling said application of the heat energy inaccordance with the number of glue lines being dried, said structureincluding means for varying the amount of electrical energy input tosaid other wave guide, said structure including means for varying theamount of electrical energy from said third wave guide to said otherwave guide.
 12. A method of removing moisture from one or more gluelines extending longitudinally along each or both marginal edges of aweb of continuous sheets, arranged in face-to-face relationship, saidmethod including the steps of: advancing the web along a path of travelparallel with said edges; subjecting said edges to a field of electricalenergy in the microwave region flowing along each of said edgesrespectively as the web is advanced, whereby the glue lines absorb saidelectrical energy to thereby apply heat energy and raise the temperatureof the glue lines, causing evaporation of said moisture thereof; andvarying the dwell time of one of said edges in one of said fields withrespect to the dwell time of the other of said edges in the other ofsaid fields whereby to control said application of the heat energy alongsaid one edge in accordance with the number of glue lines being driedalong said one edge.
 13. A method as claimed in claim 12, and varyingthe amount of electrical energy input to said other field in accordancewith the number of glue lines being dried by said other field.
 14. Adrier for removing moisture from one or more glue lines extendinglongitudinally along each or both marginal edges of a web of continuoussheets, arranged in face-to-face relationship, as the web is advancedalong a predetermined path of travel, said drier including: an elongatedwave guide adapted for conduction of electrical energy in the microwaveregion and disposed along each of said edges respectively, said waveguides having longitudinal clearance slots for passage of said edgestherealong and through the wave guides as the web is advanced, wherebythe glue lines absorB said electrical energy to thereby apply heatenergy and raise the temperature of the glue lines, causing evaporationof said moisture thereof, there being a source of said electrical energycoupled with one of said wave guides, the other of said wave guidesreceiving its electrical energy from said one wave guide through a thirdwave guide coupling the one wave guide with said other wave guide; andstructure for controlling said application of the heat energy by eachwave guide respectively in accordance with the relationship of thenumber of glue lines along one of said edges to the number of glue linesalong the other of said edges.
 15. A drier for removing moisture fromone or more glue lines extending longitudinally along each or bothmarginal edges of a web of continuous sheets, arranged in face-to-facerelationship, as the web is advanced along a predetermined path oftravel, said drier including: an elongated wave guide adapted forconduction of electrical energy in the microwave region and disposedalong each of said edges respectively, said wave guides havinglongitudinal clearance slots for passage of said edges therealong andthrough the wave guides as the web is advanced, whereby the glue linesabsorb said electrical energy to thereby apply heat energy and raise thetemperature of the glue lines, causing evaporation of said moisturethereof; and structure for controlling said application of the heatenergy in accordance with the number of glue lines being dried, saidstructure including means for varying the dwell time of one of saidedges within one of said wave guides independently of the dwell time ofthe other of said edges within the other of said wave guides.